In medicine, there is the concept of arachnophobia, which, translated into more understandable language, means fear of arachnids. Indeed, most people become irritated at the sight of these creatures for fear of being bitten.
All individuals have poisonous glands because they are predators, but not all pose a danger to humans. In our homes (from northern to southern latitudes) there live small spiders that cannot cause significant harm to humans, much less become a threat to life.
House spiders are not dangerous to humans and are useful because they catch other insects
General information
A spider bite usually causes a painful condition in humans called arachnidism or aranidism .
It is characterized by various symptoms and consequences initiated by the toxic effect of a poisonous animal. The poison can be neurotoxic or necrotic. In addition, pathogenesis is associated with allergic reactions and infection introduced into the wound. A small number of spider species are poisonous. They are the most important entomophages, destroying a huge number of insects and other species harmful to the ecosystem. In the north and in the middle zone, poisonous spiders are not found.
Representatives of the families Theraphosida, Gnaphosidae, Linyphiidae, Micryphantidae are poisonous. Their toxicity may vary depending on the season, gender, age and environment.
Spiders next to a person
Spiders often inhabit people's homes. You should not be afraid of the house spider, because it is not dangerous to humans, but has woven a web to catch insects. They do not form populations and reproduce quite rarely, especially if there is not enough food. They live for about 2-6 months.
Types of house spiders
Preventive measures
To prevent bites from various types of spiders, you must:
- Wear shoes and clothing that completely cover the body when carrying out agricultural work.
- Do not pick up spiders, especially for small children.
- Do not lie on the grass and try not to sleep in haylofts in the open air, in places where these insects are most common.
- Carry out sanitary treatment of premises in a timely manner when identifying the location of poisonous spiders.
20 most effective spider repellents
There are a large number of insects around us that can cause serious harm to our health with their poison. Therefore, correct behavior in space plays an important role, especially in the vicinity of such dangerous pests. Be as vigilant as possible when walking with children to avoid unpleasant consequences. After all, the bite of a very poisonous spider can be stronger in its actions than a viper or cobra. Take care of yourself and your loved ones!
Pathogenesis
The pathogenesis is based on the toxic effect of poisons - neurotoxic and necrotic (cytolytic), as well as the development of allergic and infectious reactions in response to a bite. Effects may be local only or with additional systemic reactions resulting from neurotoxicity.
The effect of spider venoms resembles strychnine , but is much weaker. After excitement, a loss of strength occurs and paralysis . The toxic complex biochemical mixture contains neurotoxic substances that paralyze the nervous system, as well as hemolytic substances that destroy the blood. Their main task is to kill and paralyze the victim, as well as protect and scare away the aggressor.
The mechanism of action of Latrotoxin, a component of most neurotoxic poisons
By its nature, it is a presynaptic neurotoxin, since the point of action of Latrotoxin is the presynaptic nerve ending. There, the dimeric toxin is able to contact protein receptors with a molecular weight of ~95,000, as a result of which the resulting complex induces the permeability of biomembranes and becomes a channel for calcium cations - triggering the release of neurotransmitters and accelerating this process by 1000-1500 times. When reserves are depleted, after 30-50 minutes a complete block of neuromuscular transmission occurs. This ultimately leads to overstimulation of the muscle motor neuron ganglia.
How it bites
This arthropod is not one of the blood-sucking insects and does not require blood for food. The spider bites in self-defense if it feels trapped.
The insect's chelicerae (fangs) are small, in most cases they are not able to pierce the skin, so the bite can go unnoticed by humans. The poison-conducting channels are located directly in them, so toxins are injected at the moment of puncture.
Classification
When bitten by a spider, it is very important to know what type of insect attacked you or your loved ones. It is best if you can photograph the spider, but in most cases you have to rely on developing clinical manifestations.
Cross spider bite
The spider's venom is generally toxic to arachnids and insects. Toxicity is determined by the location of administration - the closer to the ganglion, the stronger the effect.
Cross spider bites can cause
headache , weakness , arthralgia , colic and burning at the site of the bite with hemorrhages into the subcutaneous tissue. No deaths have been reported, but a spider bite after recovery quite often initiates a secondary infection and necrosis of soft tissue in the area of penetration of the venom. The eggs themselves and the body of the spider, especially at the egg-laying stage, contain a toxic substance - epeirotoxin .
Black widow bite
More people on the planet died from black widow bites than from all other spiders combined, so even the pathological condition they caused was given a name - latrodectism .
The black widow's bite is neurotoxic, only females bite, and feels like a pinprick. In appearance, the bite site is characterized by two points, slight redness and swelling without the formation of necrotic wounds. The α-latrotoxin contained in the venom stimulates the release of mediators, acetylcholine , norepinephrine, etc. from presynaptic endings, causing subsequent depletion of their reserves. Before the onset of painful muscle spasms, 0.5-1 hour passes after the spider bite, and they subsequently spread to neighboring and large muscles, limbs and torso. A person feels a pronounced tension in the muscles of the anterior abdominal wall with painless palpation, but excruciating pain can cause a false suspicion of peritonitis .
External manifestations and behavior are distinguished by drooling , sweating , vomiting , hypertension , tachycardia , wheezing , anxiety , hyperreflexia , retention , muscle twitching, trembling, complaints of headache and weakness, changes in sensitivity, and in pregnant women contractions may begin prematurely childbirth _
Usually, after being bitten by a black widow, a person is in a hysterical and shocked state - running and screaming in pain. The pain usually subsides within the first 12 hours, but may intensify again in the next 24 hours and manifest itself within a week.
Dangerous spider for humans - black widow
Death usually occurs as a result of respiratory arrest or hemorrhagic stroke , failure of cardiac function, especially in young, elderly and debilitated patients.
Karakurt bite
Karakurt poison has a neurotoxic effect and has similar symptoms as in black widows. After a burning sensation in the area of the bite, redness and swelling occurs on the body, as well as pain that spreads radially to the abdomen, lower back and chest, so the condition is easily confused with myocardial infarction. General poisoning is manifested by shortness of breath , increased heart rate , dizziness , headache , tremor , vomiting , pallor, or, on the contrary, facial hyperemia , sweating , priapism , bronchospasm , exophthalmos and mydriasis , as well as delayed urination and defecation. The later stages of poisoning are characterized by a change from psychomotor agitation to deep depression , blackouts and delirium.
Tarantula bite
The venom of the tarantula is considered less powerful than the karakurt. Its rather large body is 5-7 centimeters and its paws are covered with hairs. Color ranges from dark brown to black.
The sting resembles a bee sting and is not fatal. At the site of the lesion, pain, slight swelling and swelling of the tissues occur. It is possible to develop general toxicemia , accompanied by heaviness in the body , chills , apathy , lethargy and drowsiness , which disappear on their own after a few days.
Silver Spider Bite
A separate species of spiders living in aquatic environments is common in Europe. It poses a danger to humans, as it can bite when caught during fishing with fish or when it reaches the shore. And despite the fact that a spider bite is just self-defense, its venom in people prone to allergies can cause an inflammatory reaction and severe allergic symptoms, manifested by weakness, nausea , dizziness , headache, and fever. Clinical manifestations disappear after a few days. To speed up the therapeutic effect, it is enough to take an antihistamine.
Tartar spider bite
If an allergic reaction does not develop after the bite of a tarantula spider, then its venom usually does not cause much harm to a person. It is comparable to wasps and bees.
The main allergen is “protective stinging hairs,” which can get on the skin or mucous membranes of a person and cause unbearable itching, pain when it gets into the eyes, suffocation and general weakness.
Causes
The main pathogen is toxins secreted by the mouthparts (chelicerae) of spiders:
- neurotoxic poisons (Δ-atracotoxin of the most dangerous Australian spider Atrax robustus, α-latrotoxin of the black widow and karakurt) have a direct effect on the structures of the central nervous system of the attacked individual by such representatives of spiders as karakurt and black widows;
- necrotic poisons (containing the dermonecrotic substance sphingomyelinase) are produced by spiders of the sicariid family.
It is important to remember that spiders themselves do not attack people or large animals. In dangerous situations, they prefer to flee. Worse, if a person is caught in a web or a tenet cocoon designed to catch insects, then the spider may instinctively attack the victim. However, most often spiders bite people when they accidentally crush or step on them. It is important to know that the most dangerous representatives of spiders are the Australian species Atrax robustus, since they tend to climb into human dwellings - cool and damp, where they establish their homes and trapping nets for fairly large insects and animals.
Male and female Atrax robustus
Prevention
Avoid allowing insects to breed in your home because they can be dangerous and attract other animals to feed on them. To keep animals out, you should always close the doors and put mosquito nets on the windows.
The house should be cleaned regularly; cobwebs should be removed with a broom from eaves, ceilings, behind furniture and other places where insects can settle. If there is a strong proliferation of invertebrates, you need to treat the room with an aerosol insecticide, for example, dichlorvos, raid or any other means.
Symptoms of a spider bite
Local manifestations and skin lesions usually consist of wound redness and itching, joint and muscle pain (arthralgia and myalgia), but spider bites can provoke the development of systemic disorders within a few hours and even minutes, including:
- increase in temperature, up to intense heat;
- chills;
- vomit;
- abdominal pain;
- dizziness;
- profuse sweating;
- priapism;
- hallucinosis;
- convulsions;
- hyperreflexia;
- in severe cases, coma and even death can occur.
Symptoms of a karakurt bite are similar to the clinical picture described above. depression , clouding of consciousness and delirium may occur .
What does a spider bite look like?
A spider bite usually does not look too scary; in addition to redness (erythema) and swelling, you can see two red or burgundy dots.
As you can see in the photo of a spider bite on a person’s hand, a local inflammatory reaction and necrotic processes occurred.
Necrosis after a spider bite
Arachnoism cutaneous
A spider bite can cause dermatosis - the so-called cutaneous arachnoidism , manifested by local hyperemia and edema, urticarnovesicular rashes. Local symptoms may develop against the background of cramps and diarrhea.
Severe disorders occur when bitten by spiders of the Lactodectus mactans and Loxosceles species.
First aid
Despite the fact that local and systemic symptoms caused by a bite usually go away spontaneously after a few hours, it is still better to know and carry out a number of preventive measures to prevent the likelihood of complications. Remember that ambulance is especially necessary for elderly people, hypertensive patients, children and pregnant women.
What to do if bitten by a spider?
It is important for anyone to know what to do if they are bitten by a spider, because a few simple steps can help save a life:
- To be able to identify the spider, try to catch it or save its body if it was crushed;
- wash the bite site with soap and water and wipe with alcohol; in general, sterilization can be carried out by the same treatment as for an infected wound;
- immobilize the affected limb;
- do not apply pressure bandages, but apply something cold, such as ice;
- take an antihistamine to prevent an allergic reaction;
- According to some reports, if a karakurt is bitten, immediate cauterization of the bite site with a match head can help.
Treatment
To reduce the spread of venom from the bite site throughout the body, immobilization of the limb is indicated. The pain is relieved by performing a novocaine blockade, and painkillers are administered: non-narcotic and narcotic analgesics. Cold is applied to the bite area.
Hormones, antihistamines are administered: blockers of H1 receptors (promethazine (diprazine), chloropyramine (suprastin), etc. and H2 receptors (cimetidine, ranitidine (acylok), etc., vitamins. When excited, benzodiazepines are prescribed. If a karakurt is bitten, an anti-karakurt drug is administered subcutaneously serum. In severe cases, equine immunoglobulin (IgG) is administered. The antitoxin (from horse serum) prevents the venom from binding to presynaptic membranes and remains effective even 46 hours after the bite.
When a scorpion stings, calcium channel blockers and ACE inhibitors are prescribed.
Propranolol (anaprilin) effectively and quickly stops tachyarrhythmia, but does not improve hemodynamic parameters. In case of respiratory depression, oxygen is supplied; in case of acute respiratory failure, artificial pulmonary ventilation (ALV) is performed. https://medicalit.ru/wp-content/uploads/2014/03/otshelnik.jpg https://medicalit.ru/wp-content/uploads/2014/03/otshelnik-300×272.jpg2020-09-13T17 :49:31+00:00 adminPoisoning with venoms from snakes, insects, fish, the bite of a spider is a frequent and unpleasant case. Since all spiders are poisonous to one degree or another, it is necessary to treat this with caution and it is advisable to immediately seek medical help. Spiders (arachnids) are silent killers that cause instant death of their victim in the event of an attack. Patient and calculating, they weave from invisible sticky...admin [email protected] Medical literature online
Diet for spider bites
Hypoallergenic diet
- Efficacy: therapeutic effect after 21-40 days
- Timing: constantly
- Cost of products: 1300-1400 rubles. in Week
A spider bite can cause an allergic and inflammatory reaction, as well as hemolysis and decreased immunity, so the patient’s diet should be as gentle, balanced and healthy as possible. Drinking plenty of fluids is also recommended, so it would be good to base your menu on dishes such as:
- broths;
- liquid porridge;
- stewed vegetables and salads;
- fruit salads;
- dairy products;
- compotes and soothing herbal teas.
Complications and consequences of a spider bite
After being bitten, a person may develop eosinophilia . It is more typical for tarantulas, tarantulas and other types of tropical spiders, as well as scorpions.
The severe consequences of a spider bite are reduced to hemorrhages and secondary infection at the site of the bite. A tarantula bite can have irreparable consequences for a person, but more often the danger comes from pathogenic microorganisms on hooks and chelicerae that can get into the wound.
The most severe and rare consequences of a black widow bite, which lead to rhabdomyolysis and kidney failure . Also quite dangerous to human health are spiders of the genus Steatoda, otherwise called false black widows, since their bite causes steatodism (acute pain, fever for 2-48 hours).
